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Appendix A
Eagle 450 Upgrade Instructions, Rev. A00
Figure A-1 shows an extended active external narrow SCSI connector and bail locks for holding the
terminator in place. The terminator is installed by sliding it over the connector and then latching the bail
locks into the notches in the terminator.
ATTACHING EXTERNAL DEVICES
To attach an external SCSI device, you must remove the terminator from the external SCSI port.
However, you must make sure the SCSI bus is still terminated at both ends. To do so, install the external
active terminator in the unused SCSI I/O port of the external SCSI device.
Attaching an external narrow SCSI device, such as a CD-ROM drive, to a system using the Wide SCSI
bus is a special case. You must make sure all 16 lines of the Wide SCSI bus are properly terminated. To
do so:
1.
Use an external wide to narrow SCSI cable which actively terminates the “high” nine lines of the
Wide SCSI bus. Alpha Micro offers this cable in both three foot and six foot lengths
(PDB-00440-80 and PDB-00440-81).
2.
Plug the narrow active external terminator provided with your Roadrunner mounting kit
(PRA-00222-21) into the unused SCSI I/O port of the external device. This terminates the “low”
half of the SCSI bus.
Notice that, in this configuration, the Wide SCSI active external terminator (PRA-00222-20), which is
normally plugged into the external SCSI port, is not used.
TERMINATOR POWER
For information on how to configure terminator power, see the installation instructions for your tape
drive and/or the configuration document accompanying your disk drive. In almost all cases, all devices
should be configured to accept termination power from the SCSI bus. The host controller on the AM-138
supplies termination power.
